Postplus Shared

This is the rulebook that other PostPlus skills reference when they need shared conventions. It consolidates research preferences, product selection logic, TikTok music workflows, ads workflows, and source-of-truth file locations so you don't get conflicting instructions across the PostPlus family. You'll use it when another PostPlus skill explicitly asks for shared rules, at which point you read the relevant reference doc and apply it before moving to platform-specific work. The skill is instruction-only and deliberately fails if it finds a conflict instead of guessing. Think of it as the config file that keeps a multi-skill system consistent.